/**
 * 拉普拉斯算子
 * 1. GaussianBlur()
 * 2. cvtColor()
 * 3. Laplacian()
 * 4. convertScaleAbs()
 */

#include <opencv2/imgproc.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>

using namespace cv;

int main(int argc, char *argv[]) {
    //![variables]
    // Declare the variables we are going to use
    Mat src, src_gray, dst;
    int kernel_size = 3;
    int scale = 1;
    int delta = 0;
    int ddepth = CV_16S;
    const char *window_name = "Laplace Demo";
    //![variables]

    //![load]
    const char *imageName = argc >= 2 ? argv[1] : "lena.jpg";

    src = imread(samples::findFile(imageName), IMREAD_COLOR); // Load an image

    // Check if image is loaded fine
    if (src.empty()) {
        printf(" Error opening image\n");
        printf(" Program Arguments: [image_name -- default lena.jpg] \n");
        return -1;
    }
    //![load]

    //![reduce_noise]
    // Reduce noise by blurring with a Gaussian filter ( kernel size = 3 )
    GaussianBlur(src, src, Size(3, 3), 0, 0, BORDER_DEFAULT);
    //![reduce_noise]

    //![convert_to_gray]
    cvtColor(src, src_gray, COLOR_BGR2GRAY); // Convert the image to grayscale
    //![convert_to_gray]

    /// Apply Laplace function
    Mat abs_dst;
    //![laplacian]
    Laplacian(src_gray, dst, ddepth, kernel_size, scale, delta, BORDER_DEFAULT);
    //![laplacian]

    //![convert]
    // converting back to CV_8U
    convertScaleAbs(dst, abs_dst);
    //![convert]

    //![display]
    imshow(window_name, abs_dst);
    waitKey(0);
    //![display]

    return 0;
}
